Many applications require the specific capability of freezing a product in an extremely short time. Exemplary users include companies that require plasma or blood related products to be frozen quickly and completely to −40 C. Such companies contain their product in a multiplicity of specially formulated plastic bags that contain between 250 cc and 500 cc of plasma or blood related products. These companies may freeze up to 100 bags simultaneously, placing approximately 10 bags on a tray and up to 10 trays in the freezer. Traditionally, cooling devices known in the industry as Blast Freezers are used with the unique capability of freezing the customer's products at a substantially faster rate than standard laboratory or storage freezers.
Typically, state of the art Blast Freezers are mechanical, with compressors and refrigerants. The main drawback is that the boiling point of the refrigerant is approximately −100 C which severely limits the ability to freeze product quickly. As an example, these freezers are unable to freeze a batch of 100 bags to −40 C in less than 2 hours.